Ben Sainsbury

Here is an example taken from the latest GFS P run from Tue 15th at 3 & 6pm. It's not right.

Bizarrely GFS P precipitation charts on Netweather are broken and seem to show continuous precipitation over the whole map on various frames.

850hpa is approx 1km up into the atmosphere. According to environmental lapse rate as temp declines by about 10’c per km. I’d expect temperatures to struggle to get above 1’c at a max, if there is snow cover temperatures wouldn’t get above freezing. All depends on air flow too which affects lapse rate.

What -8 uppers and thickness < 512 dam?

Check that out, the GFS P with a 1050mb high over Greenland, looking forward to this. Quicker route to cold bc of orientation of the high. EDIT: 1055mb! Is a breathtaking run.

Really depends on the surface cold too... If temperatures are at 1'c or so max, then snow is possible as long as uppers remain below zero.

Unfortunately the high sinks thereafter...

I think we're just seeing a change in the orientation of the high.

That is some serious WAA off the west coast of Greenland here's hoping the high pressure in the Atlantic joins with that in Greenland. Strengthened to a 1040mb high now.

For the next few weeks I'm not too bothered about having really cold uppers at the moment. As long as we can have high pressure over us/nearby then the surface will naturally cool at this time of year and would expect the cold pool to grow over continental Europe.

Yeah a fellow course mate said it was sleeting too. Funny enough I am studying Meteorology at the Uni so I've had a good look round the weather facilities so far!

Now at Reading Uni it's difficult to know what regional chat I should be in. Nevertheless it is beginning to precipitate with a moderate intensity here, being on top floor of a halls of residence makes it difficult to see but looks to be a tad sleety.

Whilst 1hr timescales are useful you're right. Ultimately how successful a model is, is dependent on its verification stats (a judge of how accurate they are when modelling the weather) and currently the GFS Para is verifying better than the main GFS model hence why the Para is going to take over.

I second this, I think many will be surprised. Along with 850hpa temps you also (from experience) can look at dew point (<0'c), thickness of the air and elevation etc. The GFS shows fairly borderline 850hpa temps and dewpoints. The ECMWF on the other hand maybe a degree or so lower than what the GFS is showing for both 850hpa and dew-point. The higher resolution NetWx NMM model, whilst cannot view dew-points, the 850hpa's are also lower than -5'c and thickness of the air remains lower than 528 dam which is generally what you need for falling snow. Settling snow however is a different matter. We shall see!

If we are going to be looking within the next 5 days on the GFS model, it's also a good idea to look back at what the GFS was modelling for today back on Sunday. Sunday 6z and Today 6z: I must say the GFS has done exceptionally well within the 120hr timescale for the last few days.

Shame to have missed the storm near Wells given I'm at university now! Few nice CB's here out of my window, lucky to be on the top floor in my hall!

Never mind, the models looking a lot more progressive now and thundery breakdown looks unlikely.

Looks like a possible plume event indicated by NMM & GFS for Tuesday into Wednesday, one to keep an eye on.

Certainly not a bad looking feature.

The showers coming in off the Bristol Channel seem to have relatively low max heights. Wouldn't seem a positive sign in regards to Thunder.

Yes potentially, we'll have a better idea later.

Yeah this is what we should be focusing on! Given the large DLS I would expect it to develop and become more organised in the next few hours whilst becoming more thundery.

For us in the SW and Wales, 2 new sferics detected outside to sea to our west. Something to monitor over the next few hours.

Indeed it is, Nick highlighted the potential in his storm forecast. Busy right now I'll update later.

Anyone can get any pictures of the line of storms?